Educational Wealth: Astronomy

Galaxies

Abdullah 0 Astronomy Friday, March 07, 2014

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<b><span style="font-size: large;">The universe:</span></b></h3>
<span style="font-size: large;"> Air, soil,<b> <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank">rocks</a></b>,<b> stars</b>, <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>planets</b></a> and all the objects present in space are called the Universe.

The universe is so vast that its vastness could not be measured so far. Our earth is just like a small particle in it.  </span><br />
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<b><span style="font-size: large;"> Big bang theory: </span></b></h3>
<span style="font-size: large;"> The scientists present the big bang theory for explaining the beginning of the universe. </span><br />
<span style="font-size: large;">According to the theory: </span><br />
<span style="font-size: large;">The whole matter of the universe was condensed at one place about 15 billion years ago. It was in the form of extremely huge and dense ball of hydrogen. A tremendous explosion occurred in this ball. This explosion is called “Big Bang”.

Due to this explosion, the whole condensed matter scattered far away in the.</span><br />
<span style="font-size: large;"> After this explosion (Big bang), the universe assumed the form of gigantic clouds of extremely hot, expanding and contracting gases, which, with the passage of time, scattered far away from each other.

After about one million years, these clouds of gases got frozen and started shrinking resulting in the formation of galaxies and stars.

These galaxies are moving away from the center and the universe is continuously expanding. </span><br />
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<span style="font-size: large;"> Nebulae:</span></h3>
<span style="font-size: large;"> If we look at the sky during night without telescope, we see numerous stars. During night, some patches of dim light on the sky are also seen to us. These patches are called nebula.

Nebula is a Latin word which means “cloud”. Actually the huge clouds of gases and dust in space are called nebula. When these gases reflect the light of stars, then nebula looks illuminated. </span><br />
<span style="font-size: large;">The contracting and freezing of nebula forms stars.</span><br />
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<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglQtcsREmSKy7H-eWRpapyaKDlXCH4CkOKP0AwiMnBbMGdMWzdWLKRoqqcQCx63ZOhoKnhfsoCbiQXFzMlMe7W6-bYXrtF4CJxqtGB176sV1i8yn1M81ulzQoTjljA-eyYoaCaM_67sq4/s1600/sun.bmp" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="317" loading="lazy" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEglQtcsREmSKy7H-eWRpapyaKDlXCH4CkOKP0AwiMnBbMGdMWzdWLKRoqqcQCx63ZOhoKnhfsoCbiQXFzMlMe7W6-bYXrtF4CJxqtGB176sV1i8yn1M81ulzQoTjljA-eyYoaCaM_67sq4/s1600-rw/sun.bmp" width="400" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">Nebulae</td></tr>
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<span style="font-size: large;"><b>Galaxy</b> </span><br />
<span style="font-size: large;">A nebula consists of several billion stars.The family of stars is called “galaxy”. </span><br />
<b><span style="font-size: large;"> Number of galaxies</span></b><br />
<span style="font-size: large;"> There are at least one billion galaxies in the universe and the universe is so vast that most of the galaxies are several hundred thousands light years away from each other, Hence, these galaxies look like dim bulbs of light in the sky. </span><br />
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<span style="font-size: large;">Milky way Galaxy: </span></h3>
<span style="font-size: large;"> Our solar system is also a part of a galaxy, called “Milky Way Galaxy”

There are about 100 billion stars and numerous planets, which also include our earth, in the Milky Way galaxy!

What so ever a star we see without telescope is a part of this galaxy. The diameter of Milky Way galaxy is about one hundred thousand light years. </span><br />
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<span style="font-size: large;"> Blue Giant: </span></h3>
<span style="font-size: large;">The temperature of stars is extremely high. A star whose <b>temperature</b> is greater than 15000°C is called blue giant. Such a star is extremely hot and it emits intense light.

For Example:

Deneb is a blue giant. Its temperature is usually is usually 15000°C. </span><br />
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<span style="font-size: large;">Red Giant:</span></h3>
<span style="font-size: large;"> A star whose temperature is less than 5000°C is called red giant. It is comparatively a cold star.

For Example: .

Bernard star is a red giant. Its temperature is usually 3200°C.

Arcturus is also a red giant whose temperature is about 4800°C. </span><br />
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<span style="font-size: large;">One light year</span></h3>
<span style="font-size: large;"> One light year is a distance which light covers within one year. The speed of light is 3xl05 Km per second. Light covers 9.48 x 10l2 Km in one years. </span><br />
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<span style="font-size: large;"> Small stars: </span></h3>
<span style="font-size: large;"> In terms of size, stars ranging from one and half to three times bigger than the sun are called small stars.

In the core of stars, there is an often hydrogen and helium gas. The quantity of hydrogen is much more than helium. By burning these gases, light emits from stars. In the core of star, hydrogen gas is continuously converted into helium till the complete discharge of hydrogen gas from the core, the core of star after contraction is collapsed. </span><br />
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<span style="font-size: large;">Red Giant: </span></h3>
<span style="font-size: large;"> After the collapse previous one and then the star becomes red giant. For this happening, several billion years are spent. </span><br />
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<span style="font-size: large;">White dwarfs: </span></h3>
<span style="font-size: large;">The outer layers of star while gradually expanding are converted into gases, and its size become small. This small star is called white dwarf. Its size is often equal to our Earth. </span><br />
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<span style="font-size: large;"> Red dwarf:</span></h3>
<span style="font-size: large;"> After several hundred thousands years, white dwarf after gradually cooling down goes to dim. Meanwhile red light is emitted from the core the star. Such star is called red dwarf. The diameter of red dwarf ranges from 3000 kilometers to 50000 kilometers.</span><br />
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<span style="font-size: large;"> Black Dwarf: </span></h3>
<span style="font-size: large;"> When red dwarf after having become frozen stops shining completely then such a dead star is called black dwarf. </span><br />
<b><span style="font-size: large;">Massive stars: </span></b><br />
<span style="font-size: large;"> The stars three times bigger than the sun are called “massive stars”. In the core of these stars, hydrogen gas is continuously converted into helium. This process in massive stars is usually completed within 10 million years. </span><br />
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<span style="font-size: large;"> Red supergiant: </span></h3>
<span style="font-size: large;">At the complete discharge of hydrogen gas, massive stars become “red supergiant” and their size become 1000 times enlarger than the previous one. </span><br />
<b><span style="font-size: large;">Supernova: </span></b><br />
<span style="font-size: large;"> In the next few hundred thousand years, the core of red supergaint suddenly collapses which creates a huge explosion, called “supernova”. And for the time being its light becomes much more than all other stars of the galaxy.

Neutron star:

If during supernova, the core of star is some how the sun, then the core of star contracts after freezing. And it converts into “neutron star”.</span><br />
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<span style="font-size: large;"> Characteristics of neutron star: ' </span></h3>
<span style="font-size: large;">Neutron stars are very dense and their core contains neutrons only. These stars speedily revolve and emit light whereas the black holes are known by their extreme gravity. Their gravity is so much that even light cannot escape from it.

Diameter of neutron star:

The diameter of neutron star is usually 10 kilometer. Its core is extremely dense.</span><br />
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<span style="font-size: large;"> Mass of neutron atom: </span></h3>
<span style="font-size: large;">.

One spoon mass of the material of its core is equivalent to one billion metric tones or even more than this.

Black hole:

If the mass of the core of star is three times bigger than the mass of the sun, then the core of <a href="http://educational-wealth.blogspot.com/2013/12/the-star-short-story.html" target="_blank"><b>star </b></a>contracts such a way that too much density comes on one point. </span><br />
<span style="font-size: large;">It is called “black hole”. There are several hundred thousands black holes in the Milky Way galaxy.

Black hole is actually a last stage of the life of star. The diameter of the sun is 1392000 Kilometres. According to astronomers, at any stage if it is converted into a black hole, then its diameter will only remain 6 kilometre.

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Galaxies

The universe: Air, soil, rocks , stars , planets and all the objects present in space are called the Universe. The universe is so va...

Earth's creation

Abdullah 0 Astronomy Tuesday, February 18, 2014

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<span style="font-size: large;">Earth </span></h2>
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<tr><td class="tr-caption" style="text-align: center;">The earth</td></tr>
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<span style="font-size: large;"> </span></h2>
<span style="font-size: large;">The Earth formed 4570 million years ago (mya) but the first animals with shells and bones appeared less than 600 mya. It is mainly with the help of their fossils that geologists have learned about the Earth’s history since then. We know very little about the 4000 million years before, known as Precambrian Time.

Just as days are divided into hours and minutes, so geologists divide the Earth’s history into time periods. The longest are eons, thousands of millions of years long. The shortest are chrons, a few thousand years long. In between come eras, periods, epochs and ages .The years since Precambrian . </span><br />
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<span style="font-size: large;"> Time are split into three eras: </span></h3>
<span style="font-size: large;">  Palaeozoic</span><br />
<span style="font-size: large;"> Mesozoic and </span><br />
<span style="font-size: large;">Cenozoic. </span><br />
<span style="font-size: large;">Different plants and animals lived at different times, so geologists can tell from the fossils in rocks how long ago the rocks formed. </span><br />
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<span style="font-size: large;">Fossils and earth's history </span></h3>
<span style="font-size: large;">Using fossils, they have divided the Earth’s history since Precambrian Time into 11 periods.

Layers of rock form on top of each other, so the oldest rocks are usually , at the bottom and the youngest at the top, unless they have been disturbed. </span><br />
<span style="font-size: large;">The order of layers from top to bottom is known as the geological column. By looking for certain fossils geologists can tell if one layer of rock is older than another. </span><br />
<span style="font-size: large;"> Fossils can only show if a rock is older or younger than another; they cannot give a date in years. Also, many rocks contain no fossils. To give an absolute date, radiocarbon dating is used.

Radiocarbon dating allows the oldest rocks to be dated. After certain substances, such as uranium and rubidium, form in rocks, their atoms break down into different atoms. This sends out rays, or radioactivity. </span><br />
<span style="font-size: large;">By assessing how many atoms in a rock have changed, geologists work out the rock’s age.

Breaks in the sequence of the geological column are called unconformities.The Solar System was created when the gas cloud left over from a giant supernova explosion started to collapse in on itself and spin. </span><br />
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<span style="font-size: large;"> Formation of earth </span></h3>
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<tr><td class="tr-caption" style="text-align: center;">creation of earth</td></tr>
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<span style="font-size: large;">About 4.55 billion years ago there was just a vast, hot cloud of dust and gas circling a new star, our Sun.

The Earth probably began when tiny pieces of space debris (called planetesimals) began to clump together, pulled together by each other’s gravity.These were like asteroids which collapse the earth oftenly.

As the Earth in the universe formed more space debris kept on smashing into it, adding new material. </span><br />
<span style="font-size: large;">This debris included <a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank"><b>ice</b></a> from the edges of the Solar System.

About 4.5 billion years ago, rock the size of Mars crashed into Earth. Splashes of material from this crash clumped together to form the <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank"><b>Moon</b></a>.

The collision that formed the Moon made the Earth very hot.

Radioactive decay heated the Earth even further.For a long time the surface of the Earth was a mass of erupting volcanoes.Iron and nickel melted and sank to form the core.</span><br />
<span style="font-size: large;"> Aluminium, oxygen and silicon floated up and cooled to form the crust

The Earth is the third planet out from the Sun, 149.6 million km away on average. On 3 January, at the nearest point of its orbit (called the perihelion), the Earth is 147,097,800 km away from the Sun. On 4 July, at its furthest (the aphelion), it is 152,098,200 km away. </span><br />
<span style="font-size: large;">The Earth is the fifth largest planet in the Solar System, with a diameter of 12,756 km and a circumference of 40,024 km at the Equator.

The Earth is one of four rocky planets, along with Mercury, Venus and <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Mars</b></a>. It is made mostly of <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank"><b>rock</b></a>, with a core of iron and nickel. No other planet in the solar system has water on its surface, which is why Earth is uniquely suitable for life.

It is the only planet known to support life. </span><br />
<span style="font-size: large;">Over 70 percent of Earth’s surface is under water.The water is present in <a href="http://educational-wealth.blogspot.com/2014/02/worlds-rivers.html" target="_blank"><b>river</b></a>s which come from the mountains when ice melts on it, and in oceans and seas,The Earth’s atmosphere is mainly harmless nitrogen and life-giving oxygen, and it is over 700 km deep. The oxygen has been made and maintained by plants over billions of years. The Earth formed 4.65 billion years ago from clouds of space dust whirling around the Sun. The planet was so hot that it was molten at first. Only slowly did the surface cool into a hard crust. </span><br />
<span style="font-size: large;">The Earth’s orbit around the Sun is 939,886,400 km long and takes 365.242 days. The Earth is tilted at an angle of 23.5°. Even so, it orbits the Sun in a level plane, called the plane of the ecliptic.The Earth is made up of the same basic materials as meteorites and the other rocky <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>planets</b></a> - mostly iron (35 percent), oxygen (28 percent) magnesium (17 percent) silicon (13 percent) and nickel (2.7 percent). Most of the Fourth's rocky crust is drowned beneath oceans, formed from steam belched out by volcanoes early in the planet’s history. </span><br />
<span style="font-size: large;">The Earth is just the right distance from the Sun for surface temperatures to stay an average 15°C, and keep most of its water liquid. The Earth is protected from the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a>’sradiation by a magnetic field.I which stretches 60,000 km out into space.

The study of the shape of the Earth is called geodesy.</span><br />
<span style="font-size: large;"> In the past, geodesy depended on ground-based surveys. Today, satellites play a major role.

The Earth is not a perfect sphere. It is a The ancient Greeks realized that the Earth is a globe. Satellite measurements show that it is not quite perfectly round.

The Earth spins faster at the Equator than at the Poles, because the Equator is farther from the Earth’s spinning axis. </span><br />
<span style="font-size: large;">The extra speed of the

Earth at the Equator flings it out in a bulge, while it is flattened at the Poles.Equatorial bulge was predicted in 1687 by Isaac Newton.

The equatorial bulge was confirmed 70 years after Newton - by French surveys in Peru by Charles de La Condamine, and in Lapland by Pierre de Maupertuis.

The Earth’s diameter at the Equator is 12,758 km. This is larger, by 43 km, than the vertical diameter from North Pole to South Pole.

The official measurement of the Earths radius at the Equator is 6,376,136 m plus or minus 1 m. </span><br />
<span style="font-size: large;">The Lageos (Laser Geodynamic) satellite launched in 1976 has measured gravitational differences with extreme precision. It has revealed bumps up to 100 m high, notably just south of India.

The Seasat satellite confirmed the Axis ocean surfaces are South pole geoid. </span><br />
<span style="font-size: large;">It took millions m North poie of measurements of the height of the ocean surface, accurate to within a few centimetres. The Earth rotates around its axis, the imaginary line running through the centre of the planet from pole to pole at an angle of 23.5°. </span></div>

Earth's creation

Earth The earth The Earth formed 4570 million years ago (mya) but the first animals with shells and bones appeared less than 600...

Mars and venus (planets)

Abdullah 0 Astronomy Thursday, February 13, 2014

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<span style="font-size: large;">Mars (planet)</span></h3>
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<tr><td class="tr-caption" style="text-align: center;">Mars (planet)</td></tr>
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<span style="font-size: large;">Mars is viewed as a distinct, reddish object, and is more prominent in some years than others. Consult a current astronomy magazine.

Since Mars is farther from the Sun than <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank">Earth</a> is, it can appear anywhere in the sky. It doesn't stay close to the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a> like the inner planets do.

When closest to Earth, it can be  a mere 38 million miles from us and twice as bright as Sirius, the bright- est star. At other times, the eccentricity of its orbit may place it about 250 million miles away. </span><br />
<span style="font-size: large;">This far from Earth it looks tiny even through small telescopes.

Using a telescope you may be able to see Mars's polar caps grow or shrink as seasons change.

Using a <b>telescope</b> you may also be able to see the dark surface features in its southern hemisphere.

In the northern hemisphere, you may see Mare Acidalium.If you don't see any details on Mars, there might be a dust storm brewing.

It undergoes climate change.</span><br />
<span style="font-size: large;">About 3 billion years ago, the Red Planet had extensive flowing water and then fell quiet Mars' climate has been much more dynamic.It has high concentrations of boron . When present in its oxidized form (borate), boron is very important in the formation of RNA. </span><br />
<span style="font-size: large;">Borates are also present which can stabilize ribose, a component of RNA.

<a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank">Ice</a> packs and <a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank">glaciers</a> flowed in localized areas in the last hundred million years.Martian climate may change again. and could bolster speculation about whether the Red Planet can, or did, support life.A covering of water ice mixed with dust mantled the surface of it..</span><br />
<span style="font-size: large;">"During a Martian ice age, polar warming drives water vapor from polar ice into the atmosphere. The water comes back to ground at lower latitudes as deposits of frost mixed with dust. This ice-rich mantle smooths the contours of the land. When ice at the top of the mantling layer sublimes back into the atmosphere, it leaves behind dust.

The Martian climate is overcome by sublimation, the process by which solid substances are transformed directly to vapor. </span><br />
<span style="font-size: large;"> There is a clear, semi-circular lobe that had spilled from an tributary on to the plain. The lobe is imposed on a ice deposit
Mars landing

In the 1970s the US Vikings 1 and 2 and the Soviet Mars 3 and 5 probes all reached the surface of Mars.

Mars 3 was the first probe to make a soft landing on Mars, on 2 December 1971, and sent back data for 20 seconds before it unexpectedly fell silent.

Viking 1 sent back the first colour pictures from Mars, on 26 July 1976. </span><br />
<span style="font-size: large;">The aim of the VtTcmg missions was to find signs of life, but there were none. Even so, the Viking landers sent back plenty of information about the geology and atmosphere of Mars.

On 4 July 1997, the US Mars Pathfinder probe arrived on Mars and at once began beaming back ‘live’ TV pictures from the planet’s surface.Mars Pathfinder used air bags to cushion its landing on the planet’s surface.</span><br />
<span style="font-size: large;">Two days after the Pathfinder landed, it sent out a wheeled robot vehicle called the Sojourner to survey the surrounding area.

The Sojourner showed a rock-strewn plain which looks as if it were once swept by floods.

Pathfinder and Sojourner operated for 83 days and took more than 16,000 photos.</span><br />
<span style="font-size: large;"> Missions to Mars early in the 21st century may include the first return flight after 2010.

The Mars Pathfinder mission provided many stunning images of the surface of the ‘red planet’, many taken by the Sojourner as it motored over the surface. </span><br />
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<span style="font-size: large;">Mar’s moons </span></h3>
<span style="font-size: large;">There are two moons of mars . </span><br />
<span style="font-size: large;"> (1) Phobos</span><br />
<span style="font-size: large;"> (2) Deimos </span><br />
<h4 style="text-align: left;">
<span style="font-size: large;">Phobos (Mars moon)</span></h4>
<span style="font-size: large;"> It is very smaller as compared to earth's moon. It is very irregular in shape. It is twenty seven km long in it's longest dimension.It is actually small chunk of <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank"><b>rocks </b></a>in orbit of Mars.Phobos makes three orbits in a day because it is only three thousand miles above the surface of mars. </span><br />
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<span style="font-size: large;">Deimos </span></h3>
<span style="font-size: large;"> It is fifteen km long in it's longest dimension. It is also irregular in shape and isvery smaler in size.Deimos orbits in about thirty hours.

The moons of Mars were not formed in the same way as the <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a>'s Moon formed . They are actually pieces of larger objects broken apart in a collision. Such moons may be formed from collisions of objects in orbit around the planet. </span><br />
<span style="font-size: large;">We shall find many such small moons around the giant <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>planets</b></a> like Jupiter and <a href="http://educational-wealth.blogspot.com/2014/02/very-beautiful-saturn-rings.html" target="_blank">Saturn.</a>When we think of a moon, we think of the large whitish lighted circular ball that we see at night and sometimes during the day.But the moon of mars is not typical <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank">moon</a>s in the solar system. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><b>Venus</b> </span></h3>
<span style="font-size: large;">Venus is the second planet out from the Sun - its orbit makes it 107.4 million km away at its nearest and 109 million km away at its furthest.

Venus shines like a star in the night sky because its thick atmosphere reflects sunlight amazingly well. </span><br />
<span style="font-size: large;">This planet is the brightest thing in the sky, after the Sun and the Moon.

Venus is called the Evening Star because it can be seen from Earth in the evening, just after sunset. It can also be seen before sunrise, though. It is visible at these times because it is quite close to the Sun.

Venus’s cloudy atmosphere is a thick mixture of carbon dioxide gas and sulphuric acid. </span><br />
<span style="font-size: large;">Venus is the hottest planet in the Solar System, with a surface temperature of over 470 °C. Venus is so hot because the carbon dioxide in its atmosphere works like the panes of glass in a greenhouse to trap the Sun’s heat. This overheating is called a runaway greenhouse effect.

Venus’s thick clouds hide its surface so well that until space probes detected  a view of a 6 km-high volcano on very high temperatures some people Venus’ surface called Maat Mons. </span><br />
<span style="font-size: large;">It is not thought there might be jungles beneath an actual photograph, but was created on the clouds computer from radar data collected by the Magellan orbiter, which reached Venus in the 1980s. The colours are what astronomers guess them to be from their knowledge of the chemistry of Venus. </span><br />
<span style="font-size: large;"> Venus’s day (the time it takes to spin round once) lasts 243 Earth days - longer than its year, which lasts 224.7 days. But because Venus rotates backwards, the Sun conies up twice during the planet’s yearly orbit - once every 116.8 days. </span><br />
<span style="font-size: large;"> Pressure on the surface of Venus is 90 times greater than that on Earth.

Venus is the nearest planet to Earth in size, measuring 12,102 km across its diameter.

Venus’s thick clouds of carbon dioxide gas and sulphuric acid reflect sunlight and make it shine like a star, but none of its atmosphere is transparent like the Earth’s. This makes it very hard to see what is happening down on its surface.

</span></div>

Mars and venus (planets)

Mars (planet) Mars (planet) Mars is viewed as a distinct, reddish object, and is more prominent in some years than others. Consult a...

Temprature of the earth

Abdullah 0 Article, Astronomy Wednesday, February 12, 2014

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<span style="font-size: large;">The Earth’s Tilt </span></h3>
<span style="font-size: large;">Some parts of the earth heated much more than others. To understand this we have to consider how the <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>earth</b></a> moves. The earth rotates (turns) on its axis, an imaginary line that connects the North and South Poles, once every twenty-four hours. This spinning motion makes the sun appear to move from east to west and causes day and night on earth. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;">Rotation</span></h3>
<span style="font-size: large;"> Rotation is the normal motion (movement) of most space objects. Rotate means ‘spin’.

Stars spin, planets spin, moons spin and galaxies spin - even atoms spin.

Moons rotate around planets, and <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>planets</b></a> rotate around stars. The Earth rotates once every 23.93 hours. This is called its rotation period.

We do not feel the Earth’s rotation - that it is hurtling around the Sun, while the Sun whizzes around the galaxy - because we are moving with it.

Things rotate because they have kinetic (movement) energy. </span><br />
<span style="font-size: large;">They cannot fly away because they are held in place by gravity, and the only place they can go is round.

The fastest rotating planet is Saturn, which turns right around once every 10.23 hours.

The slowest rotating planet is Venus, which takes 243.01 days to turn round. </span><br />
<span style="font-size: large;"> The Sun takes 25.4 days to rotate, but since the Earth is going around it too, it seems to take 27.27 days.

The fastest spinning objects in the Universe are neutron stars - these can rotate 500 times in just one second. Rotating galaxies are just part of the spinning, moving universe.

clip_image002

Rotation in universe

The sun is approximately 150 000 000 kilometres (93 000 000 miles) from earth. </span><br />
<span style="font-size: large;">The earth revolves (goes around) the sun once every year. In 365 days the earth travels a distance of 958 million kilometres (595 million miles) around the sun. This path is called the earth's orbit. The tilt of the earth's axis and the earth's revolution around the sun cause the change in seasons.</span><br />
<span style="font-size: large;"> How summer forms

For half the year, the Northern Hemisphere is tilted toward the sun causing summer.
How winter forms

For other half of the year, the Northern Hemisphere is tilted away from the sun. That's when we have winter. The equator receives direct sunlight all year round.

The highest temperature ever recorded on earth was 58° C (136° F.) at Al Azizyah, Libya and that the lowest ever recorded was-88° C (-127° F) at Vostok in Antarctica.These are extremes. </span><br />
<span style="font-size: large;">The average surface temperature on earth is 14° C (57° F).

In order to take temperatures, a thermometer is used to record temperature changes. Mercury is a metal that is used in this instrument. Metals expand when they are heated and contract when the temperature drops. The mercury is contained in a bulb at the end of a long narrow glass tube. </span><br />
<span style="font-size: large;">When the temperature rises, the mercury expands in the bulb and is pushed up the tube. A scale is marked on the thermometer showing the degrees of temperature rise. The two most common temperature scales used on thermometers are Celsius and Fahrenheit. At very low temperatures alcohol, not mercury, is used because it has a lower freezing point. </span><br />
<span style="font-size: large;"> If you live in a climate where temperatures are bitter cold in winter, you can understand why people wait in anticipation for the first sign of warm weather. In such climates, the weather is often a daily topic of conversation. But what would it be like to live in a hot, sultry desert, or in the jungles of <a href="http://educational-wealth.blogspot.com/2014/03/antarticaafrica-worlds-largest-continent.html" target="_blank"><b>Africa</b></a>, or perhaps far north in the Arctic regions. </span><br />
<span style="font-size: large;">The temperature affects our moods, our choice of clothing, our jobs and our overall lifestyle.

Over the past while there has been an enormous amount of talk with relation to our environment and, more specifically, "The Greenhouse Effect". You may be somewhat puzzled as to what this "Greenhouse Effect" actually is. To increase your awareness and knowledge read the information that follows.

As heat from the sun enters our atmosphere a certain percentage is reflected back into space mostly by the clouds.</span><br />
<span style="font-size: large;"> But close to 50% of the sunlight reaches the earth's surface to heat the land and waters. Heat then comes from the land and waters to warm the atmosphere. The atmosphere absorbs the heat and it is prevented from passing back into space because of the buildup of carbon dioxide and other gases such as chlorofluorocarbons (CFC's) and methane. </span><br />
<span style="font-size: large;">These gases act like the glass in a greenhouse. A greenhouse is a building made basically from glass where plants can be grown all year round because the greenhouse allows the sunlight in but prevents the heat from escaping. Likewise, the sun's heat in our atmosphere is trapped by gases.
How smog produces

The carbon dioxide and other gases are the direct result of human activities. Exhaust from cars and other modes of transportation, smog pouring from the smokestacks of factories, the gases released from residential and commercial heating - all contribute to this deplorable problem. </span><br />
<span style="font-size: large;">The excessive chopping of trees also aggravates the issue because trees absorb a lot of carbon dioxide.

Scientists warn us about this global warming, as it's referred to. Our planet is gradually "heating" up. If it continues it can eventually lead to widespread drought and the melting of the polar <a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank">ice</a> cap could cause coastal flooding. Generally speaking most authorities believe that it is essential that we all work together to rectify this problem. </span><br />
<span style="font-size: large;">The CFC's are also being blamed for the deterioration of the ozone layer. The ozone layer is a layer of gas called "ozone" that protects the Earth from nearly 90% of the sun's ultraviolet rays. In the late 1970's some scientists found a hole in the ozone layer over the Antarctica region. </span><br />
<span style="font-size: large;">Since then, the problem has gotten progressive worse. Exposure to an overabundance of ultraviolet rays can leac to all kinds of problems - from severe <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>sun</b></a>burn to skin cancer. In 19th centurey a treaty was signed by forty countries to take action against CFC' One common source of CFC's is the use of aerosol spray cans. </span><br />
<span style="font-size: large;"> We all have a responsibility to clean up our environment. In the garbage cans below write six ways you can help with these environmental issues.

On a T-shirt shape create an illustration and slogan which will encourage people to become more conscious of environme issues, (i.e. banning aerosol cans, plastics, recycling, the greenhouse effect, the ozone crisis, etc.) "Whether" we save our planet or not is up to us. </span></div>

Temprature of the earth

The Earth’s Tilt Some parts of the earth heated much more than others. To understand this we have to consider how the earth moves. The ...

Space telescopes and Crafts

Abdullah 0 Article, Astronomy Thursday, February 06, 2014

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<h3 style="text-align: left;">
<span style="font-size: large;">Space telescopes </span></h3>
<span style="font-size: large;">Space telescopes are launched as satellites so we can study the Universe without interference from Earth’s atmosphere. </span><br />
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<tr><td class="tr-caption" style="text-align: center;">Telescope</td></tr>
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<span style="font-size: large;">First space telescope </span></h3>
<span style="font-size: large;">The first space telescope was Copernicus, sent up in 1972.

The most famous is the <a href="http://educational-wealth.blogspot.com/2014/02/edwin-hubble-galilio.html" target="_blank"><b>Hubble space telescope</b>,</a> launchttp://educational-wealth.blogspot.com/2014/02/what-are-planets.htmlhed from a space shuttle in 1990.

Different space telescopes study all the different forms of radiation that make up the electromagnetic spectrum .</span><br />
<span style="font-size: large;"> </span><span style="font-size: large;"><b>Hubble space telescope</b> </span><br />
<div style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;"> In 1994 the crew of Discovery mended the Hubble space telescope in <b>orbit</b>.

The entire centre section of the orbiter is a cargo bay which can be opened in space so satellites can be placed in orbit</span> </span></div>
<h3 style="text-align: left;">
<span style="font-size: large;">Helios telescope </span></h3>
<span style="font-size: large;"> Helios 
was one of many space telescopes studying the Sun.

X-rays can only be picked up by space telescopes such as the Einstein, 
ROSAT and XTE satellites.

Gamma rays can only be picked up by space telescopes like the Compton 
Gamma-Ray Observatory.

The Hubble space telescope’s main mirror was faulty when it was 
launched, but a replacement was fitted by shuttle astronauts in 1994. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> </span><span style="font-size: large;">Satellites </span></h3>
<span style="font-size: large;"> A One of the many hundreds of satellites now in Earth’s orbit.

Satellites are objects that orbit planets and other space objects. Moons are natural satellites. Spacecraft sent up to orbit the Earth and the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a> are artificial satellites.

The first artificial satellite was Sputnik 1, launched on 4 October 1957.</span><br />
<span style="font-size: large;"> About 100 artificial satellites are now launched every year.

A few of them are space telescopes.
<a href="http://educational-wealth.blogspot.com/2014/01/ways-of-information.html" target="_blank">Communications</a> satellites beam everything from <a href="http://educational-wealth.blogspot.com/2014/01/ways-of-information.html" target="_blank"><b>TV</b></a>

pictures to <b><a href="http://educational-wealth.blogspot.com/2014/01/ways-of-information.html" target="_blank">telephone</a> </b>calls around the world.</span><br />
<h3 style="text-align: left;">
<b><span style="font-size: large;"> </span><span style="font-size: large;">Observation satellites</span></b></h3>
<span style="font-size: large;"> Observation satellites scan the Earth and are used for purposes such as scientific research, weather forecasting and spying. </span><br />
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<span style="font-size: large;"> </span><span style="font-size: large;">Navigation satellites </span></h3>
<span style="font-size: large;">Navigation satellites such as the Global Positioning System (GPS) are used by people such as airline pilots to work out exactly where they are. </span><br />
<span style="font-size: large;"><span style="font-size: large;"> <b>Geostationary orbit</b></span> </span><br />
<span style="font-size: large;">Satellites are launched at a particular speed and trajectory (path) to place them in just the right orbit. </span><br />
<span style="font-size: large;"> The lower a satellite’s <b>orbit</b>, the faster it must fly to avoid falling back to Earth. Most satellites fly in low orbits, 500 km above the Earth.

A geostationary orbit is 35,786 km up. Satellites in geostationary orbit over the Equator always stay in exactly the same place above the Earth. </span><br />
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<span style="font-size: large;">COBE satellite </span></h3>
<span style="font-size: large;">The COBE satellite picks up microwave radiation which may be left over from the <a href="http://educational-wealth.blogspot.com/2014/03/galaxies.html" target="_blank"><b>Big Bang</b></a>. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;">IRAS satellite </span></h3>
<span style="font-size: large;">The IRAS satellite studied infrared radiation from objects as small as space dust.

Space telescopes that study ultraviolet rays from the <b>stars</b> included the International Ultraviolet Explorer (IUE), launched in 1978.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;"> Polar orbiting satellites</span> </span></h3>
<span style="font-size: large;"> Polar orbiting satellites circle the Earth from pole to pole about 850 km up, covering a different strip of the Earth’s surface on each orbit. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;">Communications satellites</span> </span></h3>
<span style="font-size: large;"> Communications satellites act as relay stations, receiving signals from one location and transmitting them to another. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;">Spacecraft </span></h3>
<span style="font-size: large;"> There are three kinds of spacecraft -</span><br />
<span style="font-size: large;"> 1-Artificial satellites</span><br />
<span style="font-size: large;">2- unmanned probes </span><br />
<span style="font-size: large;">3-Manned spacecraft. </span><br />
<span style="font-size: large;">Spacecraft have double hulls  to protect against other space objects that crash into them.

Manned spacecraft must also protect the crew from heat and other dangerous effects of launch and landing.

Spacecraft windows have filters to protect astronauts from the Sun’s dangerous ultraviolet rays. </span><br />
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<span style="font-size: large;"><span style="font-size: large;">Flying saucers</span> </span></h3>
<span style="font-size: large;"> Supposed alien spacecraft are sometimes called ‘flying saucers’. Modern science-fiction portrays them as more like this.</span><br />
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<span style="font-size: large;">Space travel

Radiators</span></h3>
<span style="font-size: large;"> Space travel

Radiators on the outside of the spacecraft lose heat, to stop the crew’s body <a href="http://educational-wealth.blogspot.com/2014/02/temprature-of-earth.html" target="_blank"><b>temperature</b></a>s overheating the craft. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> </span><span style="font-size: large;">Manned spacecraft</span></h3>
<span style="font-size: large;"> Manned spacecraft have life-support systems that provide oxygen to breathe, usually mixed with nitrogen (as in ordinary air). </span><br />
<span style="font-size: large;">Charcoal filters out smells.

The US space shuttle, the first reusable spacecraft, has made manned space flights out into Earth’s orbit and back almost a matter of routine.

The carbon dioxide that crews breathe out is absorbed by pellets of lithium hydroxide.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> </span><span style="font-size: large;">Spacecraft toilets</span></h3>
<span style="font-size: large;">Spacecraft toilets have to get rid of waste in low gravity conditions. Astronauts have to sit on a device which sucks away the waste.</span><br />
<span style="font-size: large;"> Solid waste is dried and dumped in space, but the water is saved.

To wash, astronauts have a waterproof shower which sprays them with jets of water from all sides and also sucks away all the waste water. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;">Weightlessness of space</span> </span></h3>
<span style="font-size: large;">The weightlessness of space means that most astronauts sleep floating in the air, held in place by a few straps. </span><br />
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<span style="font-size: large;"> Rockets </span></h3>
<span style="font-size: large;"> Rockets provide the huge thrust needed to beat the pull of Earths gravity and launch a spacecraft into space.

The space shuttle uses a huge fuel tank and two booster rockets to launch.</span><br />
<span style="font-size: large;"> After launch the booster rockets fall away from the shuttle. </span><br />
<span style="font-size: large;">The shuttle uses its own power to complete its mission before returning to Earth.

Rockets burn propellant , to produce hot gases that drive the rocket upwards.</span><br />
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<span style="font-size: large;">Rocket's fuel </span></h3>
<span style="font-size: large;">Rocket propellant comes in two parts -a solid or liquid fuel, and an oxidizer. </span><br />
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<span style="font-size: large;"> </span><span style="font-size: large;">Solid fuel</span></h3>
<span style="font-size: large;"> Solid fuel is a rubbery substance that contains hydrogen, and it is usually used in additional, booster rockets. </span><br />
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<span style="font-size: large;"><span style="font-size: large;"> Liquid fuel</span> </span></h3>
<span style="font-size: large;"> Liquid fuel is usually liquid hydrogen, and it is typically used on big rockets.

There is no oxygen in space, and the oxidizer supplies the oxygen needed to burn fuel.</span><br />
<span style="font-size: large;"> It is usually liquid oxygen (called ‘lox’ for short). </span><br />
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<span style="font-size: large;"><b>First liquid fuel rocket</b> </span></h3>
<span style="font-size: large;">The first rockets were made 1000 years ago, in China.

Robert Goddard launched the very first liquid-fuel rocket in 1926.

The German V2 war rocket, designed by Werner von Braun, was the first rocket capable of reaching space.</span><br />
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<b><span style="font-size: large;">Space shuttle </span></b></h3>
<span style="font-size: large;"> Unlike other spacecraft, the space shuttle can land like an aeroplane ready for another mission. But even the shuttle has to be launched into space on the back of huge rockets. These soon fall back to Earth, where they are collected for reuse.

The most powerful rocket ever was the Saturn 5 that sent astronauts to the Moon. </span><br />
<span style="font-size: large;"> The space shuttle is a reusable spacecraft, made up of a 37.2-m-long 
orbiter, two big Solid Rocket Boosters (SRBs), three main engines and a 
tank.

The shuttle orbiter is launched into space upright on SRBs, which fall 
away to be collected for reuse. </span><br />
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<span style="font-size: large;">Orbital velocity</span></h3>
<span style="font-size: large;">The biggest problem when launching a spacecraft is overcoming the pull of Earth’s gravity.

To escape Earth’s gravity, a spacecraft must be launched at a particular velocity .</span><br />
<span style="font-size: large;"> The minimum velocity needed for a spacecraft to combat gravity and stay in orbit around the Earth is called the orbital velocity. </span><br />
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<span style="font-size: large;">Escape velocity </span></h3>
<span style="font-size: large;">When a spacecraft reaches 140 percent of the orbital velocity, it is going fast enough to break free of Earth’s gravity. </span><br />
<span style="font-size: large;">This is called the escape velocity. </span><br />
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<span style="font-size: large;"><span style="font-size: large;">Launch vehicles</span> </span></h3>
<span style="font-size: large;">The thrust (push) that launches a spacecraft comes from powerful rockets called launch vehicles.

Launch vehicles are divided into sections called stages, which fall away as their task is done. </span><br />
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<span style="font-size: large;"><span style="font-size: large;">First stage of Launch vehicles</span> </span></h3>
<span style="font-size: large;">The first stage lifts everything off the ground, so its thrust must be greater than the weight of launch vehicle plus spacecraft.</span><br />
<span style="font-size: large;"> It falls away a few minutes after take off. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;">Second stage of Launch vehicles</span></span></h3>
<span style="font-size: large;"> A second stage is then needed to accelerate the spacecraft towards escape velocity.

After the launch stages fall away, the spacecraft’s own, less powerful, rocket motors start.

To stay in orbit 200 km up, a spacecraft

has to fly at over 8 km per second. </span><br />
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<span style="font-size: large;">Wings and space craft </span></h3>
<span style="font-size: large;">A spacecraft cannot use wings to lift it off the ground, as wings only work in the lower atmosphere. Instead, launch rockets must develop a big enough thrust to power them straight upwards, overcoming gravity with a mighty blast of heat.  </span><br />
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<span style="font-size: large;">Landing of Orbitars </span></h3>
<span style="font-size: large;">When the mission is over the orbiter lands like a glider.

The orbiter can go as high as a near-Earth orbit, some 300 km above the Earth.

The maximum crew is eight, and a basic mission is seven days, during which the crew work in shirtsleeves.

Orbiter toilets use flowing air to suck away waste.

The orbiter can carry a 25,000 kg-load in its cargo bay. </span><br />
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<span style="font-size: large;">First four orbiters </span></h3>
<span style="font-size: large;"> The first four orbiters were named after old sailing ships - Columbia, Challenger, Discovery and Atlantis. </span><br />
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<span style="font-size: large;">Engines of orbitars </span></h3>
<span style="font-size: large;">The three main engines are used only for lift-off.</span><br />
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<span style="font-size: large;">Orbital Manoeuvring System (OMS)</span></h3>
<span style="font-size: large;"> In space, the small Orbital Manoeuvring System (OMS) engines take over.</span><br />
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<span style="font-size: large;"> </span><span style="font-size: large;">The Reaction Control System (RCS) </span></h3>
<span style="font-size: large;"> The Reaction Control System (RCS) makes small adjustments to the orbiter’s position.

In future, faster space planes may take over from shuttles, so that humans can visit other planets. </span><br />
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<span style="font-size: large;">Tragedy with shuttle in 1986 </span></h3>
<span style="font-size: large;">The 2003 shuttle programme was brought to an untimely end when the Columbia exploded killing all seven crew members. This tragedy echoed the ill-fated Challenger programme of 1986.</span><br />
<span style="font-size: large;">. </span><br />
<span style="font-size: large;">Space probes Voyager 2 used Saturn’s gravity to fly on to Uranus and <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Neptune</b></a>.

Space probes are automatic, computer-controlled unmanned spacecraft sent to explore space.

The first successful planetary probe was the USA’s Mariner 2, which flew past <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Venus</b></a> in 1962.  Mariner 10 reached Mercury in 1974. </span><br />
<span style="font-size: large;">Vikings 1 and 2 landed on  <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Mars</b></a> in 1976.  Voyager 2 has flown over six billion km and is heading out of the Solar System after passing close to Jupiter (1979), Saturn (1980), Uranus (1986) and Neptune (1989).

Most probes are ‘fly-bys’ which spend just a few days passing their target and beaming back data to <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a>. </span><br />
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<span style="font-size: large;"> Slingshot</span></h3>
<span style="font-size: large;">To save fuel on journeys to distant planets, space probes may use a nearby planet’s gravity to catapult them on their way.</span><br />
<span style="font-size: large;"> This is called a slingshot.</span><br />
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<span style="font-size: large;">Space probes </span></h3>
<span style="font-size: large;"> In the first ten years of the 21st century, more than 50 space probes will be sent off to visit <b>planets</b>, asteroids and comets, as well as to observe the Moon and the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a>.

Space probes will bring back samples from Mars, comets and asteroids early in the 21 st century.</span><br />
<span style="font-size: large;">Probes are equipped with a wealth of equipment for recording data and beaming it back to Earth.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"><span style="font-size: large;">Terrestrial Planet Finder (TPF)</span> </span></h3>
<span style="font-size: large;"> Terrestrial Planet Finder (TPF) may be used to detect planets circling nearby stars in 2009. </span><br />
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<span style="font-size: large;">Voyagers 1 and 2 </span></h3>
<span style="font-size: large;">The Voyagers are a pair of unmanned US space probes, launched to explore the outer planets.

Voyager 1 was launched on 5 September 1977.</span><br />
<span style="font-size: large;"> It flew past Jupiter in March 1979 and Saturn in November 1980, then headed onwards.Jupiter's orange moon. Voyager 2 discovered sulphur volcanoes on this moon, in 1979.

on a curved path that will take it out of the Solar System altogether.

Voyager 2 travels more slowly.</span><br />
<span style="font-size: large;"> Although launched two weeks earlier than Voyager 1, it did not reach Jupiter until July 1979 and Saturn until August 1981.

The Voyagers used the ‘slingshot’ of Jupiter’s gravity  to hurl them on towards <a href="http://educational-wealth.blogspot.com/2014/02/very-beautiful-saturn-rings.html" target="_blank"><b>Saturn</b></a>.

While Voyager 1 headed out of the Solar System, Voyager 2 flew past Uranus in January 1986 and <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Neptune</b></a> on 24 August 1989. </span><br />
<span style="font-size: large;">It took the first close-up photographs of the two <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank">planets</a>.

The Voyagers revealed volcanoes on Io, one of Jupiter’s Galilean moons.

Voyager 2 found ten unknown moons around <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Uranus</b></a>.

Voyager 2 found six unknown <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank"><b>moon</b></a>s and three rings around Neptune.

Voyager 2 reached <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Neptune</b></a> in 1989, revealing a wealth of new information about this distant planet.

Voyager 2 will beam back data until 2020 as it travels beyond the edges of the Solar System. </span></div>

Space telescopes and Crafts

Space telescopes Space telescopes are launched as satellites so we can study the Universe without interference from Earth’s atmosphere. ...

The Moons

Abdullah 0 Article, Astronomy Wednesday, February 05, 2014

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<span style="font-size: large;">The Moons</span></h3>
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<span style="font-size: large;">Moons are the natural satellites of planets. Most are small <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank"><b>rock</b></a> globes that continually orbit the parent planet, held in place by the planet’s gravity.

There are 65 known moons in the Solar System.

Every planet in the Solar System has a moon, apart from Mercury and <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Venus</b></a>, the nearest planets to the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a>.

New moons are frequently discovered, as space probes such as the Voyagers reach distant planets. </span><br />
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<tr><td class="tr-caption" style="text-align: center;">The Moon</td></tr>
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<span style="font-size: large;"></span><span style="font-size: large;">Moons are the natural satellites of planets. Most are small <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank"><b>rock</b></a> globes that continually orbit the parent planet, held in place by the planet’s gravity.

There are 65 known moons in the Solar System.

New moons are frequently discovered, as space probes such as the Voyagers reach distant planets. </span></div>
<span style="font-size: large;">Three moons have atmospheres - <a href="http://educational-wealth.blogspot.com/2014/02/very-beautiful-saturn-rings.html" target="_blank"><b>Saturn</b></a>’s moon Titan, Jupiter’s Io, and <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Neptune</b></a>’s Triton.

The Moon is 384,400 km from the Earth and about 25 percent of Earth’s size. </span><br />
<span style="font-size: large;">The Moon orbits the Earth once every month, with each orbit taking 27.3 days. It spins round once on its axis every 720 hours.  The Moon is the only other world that humans have ever set foot on. Because the Moon has no atmosphere or wind, the footprints planted in its dusty surface in 1969 by the Apollo astronauts are still there today, perfectly preserved. </span><br />
<span style="font-size: large;">The Moon is the brightest object in the night sky, but it does not give out any light itself. It shines only because its light-coloured surface reflects sunlight.

Only the side of the Moon lit by the

<a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a> is bright enough to see.

And because we see more of this side each month as the Moon orbits the Earth, and then less again, the Moon seems to change shape. </span><br />
<span style="font-size: large;"> These changes are called the Moon’s phases. During the first half of each monthly

cycle, the Moon waxes (grows) from a crescent-shaped new moon to a full moon. During the second half, it wanes (dwindles) back to a crescent-shaped old moon.

A lunar month is the time between one full moon and the next. </span><br />
<span style="font-size: large;">This is slightly longer than the time the Moon takes to orbit the Earth because the Earth is also moving.

The Moon has no atmosphere and its surface is simply grey dust, pitted with craters created by meteorites smashing into it early in its history.

<a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>Planets</b></a>

On the Moon’s surface are large, dark patches called seas - because that is what people once believed they were. </span><br />
<span style="font-size: large;">They are, in fact, lava flows from ancient volcanoes.

One side of the Moon is always turned away from us and is called its dark side. This is because the Moon spins round on its axis at exactly the same speed that it orbits the Earth.

Unlike the Earth’s surface, which changes by the hour, the Moon’s dusty, crater-pitted surface has remained much the same for billions of years.</span><br />
<span style="font-size: large;"> The only change happens when a meteorite smashes into it and creates a new crater.

The Moons gravity is 17 percent of the earths, so astronauts in space suits canjump 4 m high!

Laser measurements showed that, on average, the Moon is 376,275 km away from the Earth. </span><br />
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<span style="font-size: large;">Gravity on the Moon is so weak that astronauts can leap high into the air wearing their heavy space suits.
<a href="http://educational-wealth.blogspot.com/2014/02/temprature-of-earth.html" target="_blank"><b>Temperatures </b></a>reach 117°C at midday on the Moon, but plunge to -162°C at night.
Moon landing

The first Moon landing was by the unmanned Soviet probe Lunar 9, which touched down on the Moons surface in 1966. </span></div>
<span style="font-size: large;"> The first men to orbit the Moon were the astronauts on board the US Apollo 8 in 1968.

On 20 July 1969 the American astronauts Neil Armstrong and Edwin (Buzz) Aldrin became the first men ever to walk on the Moon. </span><br />
<span style="font-size: large;"> When Neil Armstrong stepped on to the Moon for the first time, he said these famous words: ‘That’s one small step for a man; one giant leap for mankind.’

Twelve men have landed on the Moon between 1969 and 1972.

The Apollo 13 mission to the Moon suffered near tragedy when an explosion ripped through the service module. </span><br />
<span style="font-size: large;">The crew managed to return to Earth using the command module.

The Moon astronauts brought back 380 kg of Moon rock.

A mirror was left on the Moon’s surface to reflect a laser beam which measured the Moon’s distance from <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a> with amazing accuracy.

</span></div>

The Moons

The Moons Moons are the natural satellites of planets. Most are small rock globes that continually orbit the parent planet, held in pl...

Asteroids and Comets

Abdullah 0 Article, Astronomy Wednesday, February 05, 2014

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<span style="font-size: large;">Asteroids </span><br />
<span style="font-size: large;">Asteroids are lumps of <a href="http://educational-wealth.blogspot.com/2014/02/rocks-of-earth.html" target="_blank"><b>rock</b></a> that orbit the Sun. They are sometimes called the minor <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>planets</b></a>.

Most asteroids - more than half a million - orbit the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a> in the Asteroid Belt, between Mars and Jupiter.

Every 50 million years, the <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b> </a>is hit by an asteroid measuring over 10 km across.

Most asteroids are in the Asteroid Belt, which lies between <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Mars</b></a> and Jupiter. </span><br />
<span style="font-size: large;"> Some distant asteroids are made of ice and orbit the Sun beyond Neptune.

A few asteroids come near the Earth. These are called Near Earth Objects (NEOs).

The first asteroid to be discovered was Ceres in 1801. It was detected by Giuseppi Piazzi, one of the Celestial Police whose mission was to find a ‘missing’ planet.

Ceres is the biggest asteroid - 940 km across, and 0.0002 percent of the size of the Earth.</span><br />
<span style="font-size: large;"> The Galileo space probe took close-up pictures of the asteroids Ida and Gaspra in 1991 and 1993.

There are half a million or so asteroids bigger than 1 km across.

More than 200 asteroids are over 100 km across.

The Trojan asteroids are groups of asteroids that follow the same orbit as Jupiter. Many are named after warriors in the ancient Greek tales of the Trojan wars.</span><br />
<b><span style="font-size: large;"> Comets</span></b><br />
<span style="font-size: large;"> Comets are bright objects with long tails, which we sometimes see streaking across the night sky.

They may look spectacular, but a comet is just a dirty ball of <a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank">ice</a> a few kilometres across.

Many comets orbit the Sun, but their orbits are very long and they spend most of the time in the far reaches of the Solar System.

A comet’s tail is made as it nears the Sun and begins to melt.</span><br />
<span style="font-size: large;"> A vast plume of gas millions of kilometres across is blown out behind by the solar wind. The tail is what you see, shining as the sunlight catches it.

Comets called periodics appear at regular intervals.

Some comets reach speeds of two million km/h as they near the Sun.

Far away from the Sun, comets slow down to 1000 km/h or so - that is why they stay away for so long.</span><br />
<span style="font-size: large;"> The visit of the comet Hale-Bopp in 1997 gave the brightest view of a comet since 1811, visible even from brightly lit cities.

The Shoemaker-Levy 9 comet smashed into Jupiter in July 1994, with the biggest crash .</span><br />
<span style="font-size: large;"> The tail of a comet always

ever witnessed.

The most famous comet of all

is Hailey’s comet Comet Kahoutek streaks through the night sky. </span><br />
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<span style="font-size: large;">Hailey s comet </span></h3>
<span style="font-size: large;"> Hailey’s comet is named after the British scientist Edmund Hailey (1656-1742).

Hailey predicted that this particular comet would return in 1758, 16 years after his death. It was the first time a comet’s arrival had been predicted.

Hailey’s comet orbits the Sun every 76 years.</span><br />
<span style="font-size: large;"> Its orbit loops between Mercury and Venus, and stretches out beyond Neptune. </span><br />
<span style="font-size: large;"> Its next visit will be in 2062.

The Chinese described a visit of Hailey’s comet as long ago as 240bc.When Hailey’s cometwas seen in 1837,

Chinese astronomers wrote that its head was as bright as <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Venus</b></a> and its tail stretched right through the sky.

Harold, King of England, saw the comet in 1066. </span><br />
<span style="font-size: large;">When he was defeated by William the Conqueror a few months later, people took the comet’s visit as an evil omen.

Hailey’s comet was embroidered on the Bayeux tapestry, which shows Harold’s defeat by William.

</span></div>

Asteroids and Comets

Asteroids Asteroids are lumps of rock that orbit the Sun. They are sometimes called the minor planets . Most asteroids - more than half...

Sun and it’s rays

Abdullah 0 Article, Astronomy Wednesday, February 05, 2014

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<span style="font-size: large;">The Sun</span></h2>
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<tr><td class="tr-caption" style="text-align: center;">The sun</td></tr>
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<span style="font-size: large;"> </span><span style="font-size: large;">Medium-sized star</span></h3>
<span style="font-size: large;">The Sun is a medium-sized star measuring 1,392,000 km across.The Sun weighs 2000 trillion tonnes - about 300,000 times as much as the Earth - even though it is made almost entirely of hydrogen and helium, the lightest gases in the Universe.

The Sun’s interior is heated by nuclear reactions to temperatures of 15 million °C. </span><br />
<h3>
<span style="font-size: large;">P<span style="font-size: large;">hotosphere</span> </span></h3>
<span style="font-size: large;">The visible surface layer of the Sun is called the photosphere. This sea of boiling gas sends out the light and heat we see and feel on <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a>.

Suns surface is a turbulent mass offlames and tongues of hot gases - very different from the even, yellowish ball we see from Earth. </span><br />
<h3>
<span style="font-size: large;"><b><span style="font-size: large;">Chromosphere</span></b> </span></h3>
<span style="font-size: large;"> Above the photosphere is the chromosphere, a thin layer through which dart flames called spicules, making the chromosphere look like a flaming forest.

Above the chromosphere is the Sun’s halo-like corona.</span><br />
<span style="font-size: large;"> The heat from the Sun’s interior

erupts on the surface in patches called granules, and gigantic, flame- like tongues of hot gases called solar prominences.The Sun gets hot because it is so big that the pressure in its core is tremendous - enough to force the nuclei of hydrogen atoms to fuse (join together) to make helium atoms. </span><br />
<span style="font-size: large;">This nuclear fusion reaction is like a gigantic atom bomb and it releases huge amounts of heat.</span><br />
<span style="font-size: large;"> Halfway out from its centre to its surface, the Sun is about as dense as water. Two-thirds of the way out, it is as dense as air.

prominence sunspot

The nuclear fusion reactions in the

Suns core send out billions of light photons every minute (see light) - but they take 10 million years to reach its surface. </span><br />
<span style="font-size: large;">The temperature of the Sun’s surface is 6000°C. Each centimetre burns with the brightness of 250,000 candles!

The Sun is made mostly of hydrogen and helium, and has many layers. It has a core, where most heat is made, then a number of layers building to the flaming chromosphere on its surface.

Sunspots

Sunspots are dark spots on the Sun’s photosphere (surface), 2000°C cooler than the rest of the surface. </span><br />
<span style="font-size: large;"> The dark centre of a sunspot is the umbra, the coolest bit of a sunspot. Around it is the lighter penumbra.

Sunspots appear in groups which seem to move across the Sun over two weeks, as the Sun rotates.

Individual sunspots last less than a day.

A Infrared photographs reveal the dark sunspots that appear on the surface of the Sun. </span><br />
<span style="font-size: large;"> The number of sunspots reaches a maximum every 11 years. This is called the solar or sunspot cycle.

The next sunspot maximum will be in the year 2002.

Earth’s weather may be warmer and stormier when sunspots are at their maximum.</span><br />
<span style="font-size: large;"> Long-term sunspot cycles are 76 and

180 years, and are almost like the Sun breathing in and out.

Observations of the Sun by satellites such as Nimbus-7 showed that less heat reaches the Earth from the Sun when sunspots are at a minimum.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;">Solar eruption</span></h3>
<span style="font-size: large;">Solar eruptions takes place on the Sun’s surface.  They flare up in just a few minutes, then take more than half an hour to die away again.

Solar flares reach temperatures of 10 million °C and have the energy of a million atom bombs.

Solar flares not only send out heat and radiation, but also streams of charged particles. </span><br />
<span style="font-size: large;"> The solar wind is the stream of charged particles that shoots out from the Sun in all directions at speeds of over a million km/h. It reaches the Earth in 21 hours, but also blows far throughout the Solar System.

Every second the solar wind carries away over a million tonnes of charged particles from the Sun.

Earth is shielded from the lethal effects of the solar wind by its magnetic field .

Solar prominences are gigantic, flame-like tongues of hot hydrogen that sometimes spout out from the Sun.Solar prominences reach <a href="http://educational-wealth.blogspot.com/2014/02/temprature-of-earth.html" target="_blank"><b>temperature</b></a>s of 10,000°C. </span><br />
<span style="font-size: large;"> Coronal mass ejections are gigantic eruptions of charged particles from the Sun, creating gusts in the solar wind which set off magnetic storms on Earth.

Magnetic storms are massive hails of charged particles that hit the Earth every few years or so, setting the atmosphere buzzing with electricity. Solar prominences can stretch for many thousands of kilometres. </span><br />
<h3 style="text-align: left;">
<span style="font-size: large;">Solar changes </span></h3>
<span style="font-size: large;"> The Sun is about five billion years old and halfway through its life - as a medium-sized star it will probably live for around ten billion years.

Over the next few billion years the Sun will brighten and swell until it is twice as bright and 50 percent bigger.

The Sun will end as a

white dwarf .</span><br />
<span style="font-size: large;">The Sun seems to burn so steadily that we take for

granted that it will be equally bright and warm all the time. In the short term, however, its brightness does seem to vary very slightly all the time, and over the next 5 billion years it will probably burn more and more ferociously.

In five billion years, the

Sun’s hydrogen fuel will have burned out, and its core will start to shrink. </span><br />
<span style="font-size: large;"> As its core shrinks, the

rest of the Sun will swell up with gases and its surface will become cooler and redder. It will be a red giant star.

The Earth will have been burned to a cinder long before the Sun is big enough to swallow it up completely.

The Sun’s brightness varies, but it was unusually dim and had no sunspots between 1645 and 1715 - this period is called the Maunder minimum.</span><br />
<span style="font-size: large;"> The Earth suffered the Little<a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank"><b> Ice Age </b></a>at this time.

More of the chemical carbon-14 is made on Earth when the Sun is

more active. The carbon-14 is taken into trees, which means scientists can work out changes in solar activity in the past by measuring carbon-14 in old wood.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> Eclipses</span></h3>
<span style="font-size: large;"> An eclipse is when the light from a star such as the Sun is temporarily blocked off by another space object.

A lunar eclipse is when the Moon travels behind the Earth, and into the Earths shadow Earth is between the Moon and the Sun.

Lunar eclipses happen once or twice every year and last only a few hours.

In a total lunar eclipse, the Moon turns rust-red.

There will be a total lunar eclipse on'3 March 2007 and 28 August 2007. </span><br />
<span style="font-size: large;">A solar eclipse</span><br />
<span style="font-size: large;">A solar eclipse is when the Moon comes between the Sun and the Earth, casting a shadow a few kilometres wide on to the Earth’s surface.

A During a total solar eclipse of the Sun, the Moon blocks out everything but the Sun s corona.

In a total eclipse of

the Sun, the Moon passes directly in front of the Sun, completely covering it so that only its corona can be seen . </span><br />
<span style="font-size: large;">There are one or two

solar eclipses every year, but they are visible only from a narrow strip of the world.

There will be a total solar eclipse on 29 March 2006 and 1 August 2008.

Solar eclipses are possible because the Moon is 400 times smaller than the Sun, and is also 400 times closer to the Earth. </span><br />
<span style="font-size: large;">This means the Sun and the <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank"><b>Moon</b></a> appear to be the same size in the sky. Today people are advised never to look up at the Sun during an eclipse or they may damage their eyes permanently. This group is waiting on a beach in Hawaii to observe a total solar eclipse. They are wearing special glasses, but these really don’t make it any safer.

Auroras

Auroras are bright displays of shimmering light that appear at night over the North and South Poles.</span><br />
<span style="font-size: large;"> The Aurora Borealis is the Northern Lights, the aurora that appears above the North Pole.

The Aurora Australis is the Southern Lights, the aurora that appears above the South Pole.

Auroras are caused by streams of charged particles from the Sun known as the solar wind  crashing into the gases of the Earth’s atmosphere. </span><br />
<span style="font-size: large;"> Oxygen gas glows yellow-green when it is hit low in the atmosphere, and orange higher up.

Nitrogen gas glows bright red when hit normally, and bright blue when ionized.

Auroras form a halo of light over the poles all the time, but they are usually too faint to see. </span><br />
<span style="font-size: large;">They flare up brightly when extra bursts of energy reach the Earth’s atmosphere from the Sun.

Auroras appear at the poles and nowhere else in the world because there are deep cracks here in the Earth’s magnetic field .

Auroras are more spectacular when the solar wind is blowing strongly.

New York and Edinburgh get an average of ten aurora displays every year. </span><br />
<span style="font-size: large;"> The Northern Lights above the <b><a href="http://educational-wealth.blogspot.com/2014/01/worlds-regions.html" target="_blank">Arctic</a> </b>Circle are among nature’s most beautiful sights. Shimmering, dancing curtains of colour - bright green rays flashing with red, and streamers of white - blaze into the darkness of the polar night</span></div>

Sun and it’s rays

The Sun The sun Medium-sized star The Sun is a medium-sized star measuring 1,392,000 km across.The Sun weighs 20...

Neptune and uranus

Abdullah 0 Article, Astronomy Wednesday, February 05, 2014

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<h3 style="text-align: left;">
<span style="font-size: large;">Neptune </span></h3>
<span style="font-size: large;"> Neptune is the eighth planet out from the Sun, varying in distance from 4456 to 4537 million km.

Neptune was discovered in 1846 because two mathematicians, John Couch Adams in England and Urbain le Verrier in France, worked out that it must be there because of the effect of its gravity on the movement of Uranus.

Neptune is so far from the Sun that its orbit lasts 164.79 <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a> years. Indeed, it has not yet completed one orbit since it was discovered in 1846. </span><br />
<span style="font-size: large;">Like Uranus, Neptune has a surface of icy cold liquid methane (-210°C), and an atmosphere of hydrogen and helium.

This photo of Neptune was taken by the Voyager 2 spacecraft in 1989. The Great Dark Spot, and the little white tail of clouds, named Scooter by astronomers, are both clearly visible.

Unlike Uranus, which is almost perfectly blue, Neptune has white clouds, created by heat inside the planet. </span><br />
<span style="font-size: large;"> Neptune has the strongest winds in the

Solar System, blowing at up to 700 m per second.

Neptune has eight moons, each named after characters from Ancient Greek myths - Naiad, Thalassa, Despoina, Galatea,

Larissa, Proteus, Triton and Nereid.
Neptune’s moon

Neptune’s moon Triton looks like a green melon, while its icecaps of frozen nitrogen look like pink ice cream.</span><br />
<span style="font-size: large;"> It also has volcanoes that erupt fountains of <a href="http://educational-wealth.blogspot.com/2014/03/worlds-glaciers-and-ice-ages.html" target="_blank"><b>ice</b></a>.

Triton is the only moon to orbit backwards.

Triton, the biggest of Neptune’s eight moons, is gradually spiralling towards Neptune and in 10 million to 100 million years time will break up and form rings round the planet. Triton’s geysers shoot out frozen nitrogen gas. </span><br />
<span style="font-size: large;">The Solar System’s largest moon is bigger than Planets </span><br />
<span style="font-size: large;">Neptune is the eighth planet out from the Sun, varying in distance from 4456 to 4537 million km. Neptune was discovered in 1846 because two mathematicians, John Couch Adams in England and Urbain le Verrier in France, worked out that it must be there because of the effect of its gravity on the movement of Uranus. Neptune is so far from the Sun that its orbit lasts 164.79 Earth years. Indeed, it has not yet completed one orbit since it was discovered in 1846.</span><br />
<span style="font-size: large;"> Like Uranus, Neptune has a surface of icy cold liquid methane (-210°C), and an atmosphere of hydrogen and helium. This photo of Neptune was taken by the Voyager 2 spacecraft in 1989. The Great Dark Spot, and the little white tail of clouds, named Scooter by astronomers, are both clearly visible. Unlike Uranus, which is almost perfectly blue, Neptune has white clouds, created by heat inside the planet. </span><br />
<span style="font-size: large;">Neptune has the strongest winds in the Solar System, blowing at up to 700 m per second. Neptune has eight moons, each named after characters from Ancient Greek myths - Naiad, Thalassa, Despoina, Galatea, Larissa, Proteus, Triton and Nereid. Neptune’s moon Neptune’s moon Triton looks like a green melon, while its icecaps of frozen nitrogen look like pink ice cream. </span><br />
<span style="font-size: large;">It also has volcanoes that erupt fountains of ice. Triton is the only moon to orbit backwards. Triton, the biggest of Neptune’s eight moons, is gradually spiralling towards Neptune and in 10 million to 100 million years time will break up and form rings round the planet. </span><br />
<span style="font-size: large;">Triton’s geysers shoot out frozen nitrogen gas. orbiting Jupiter. The Solar System’s largest moon, it is bigger than <a href="http://educational-wealth.blogspot.com/2014/02/what-are-planets.html" target="_blank"><b>Planets</b></a> Neptune is the fourth largest planet. At 49,528 km across, it is slightly smaller than Uranus - hut it is actually a little heavier. </span><br />
<span style="font-size: large;">Like Uranus, its oceans of incredibly cold liquid methane make it a beautiful shiny blue, although Neptune's surface is a deeper blue than that of Uranus. Again like Uranus, Neptune has a thin layer of rings. But Neptune’s are level, and not at right angles to the Sun. Neptune has a Great Dark Spot, like Jupiter’s Great Red Spot, where storms whip up swirling clouds.</span><br />
<span style="font-size: large;"> Neptune’s moon Triton is the coldest place in the Solar System, with surface temperatures of -236°C There are little white tail of clouds and great dark spots on Neptune. These clouds are named scooter by scientists. These can clearly be seen in this photo taken by Voyager 2 space craft in 1989. Uranus Uranus is the seventh planet out from the Sun. Its orbit keeps it 1784 million km away on average and takes 84 years to complete.</span><br />
<span style="font-size: large;"> Uranus tilts so far on its side that it seems to roll around the Sun like a gigantic bowling ball. The angle of its tilt is 98°, in fact, so its equator runs top to bottom. This tilt may be the result of a collision with a meteor or another planet a long time ago. In summer on Uranus, the Sun does not set for 20 years. In winter, darkness lasts for over 20 years. </span><br />
<span style="font-size: large;">In autumn, the Sun rises and sets every nine hours. Uranus has 17 moons, all named after characters in William Shakespeare’s plays. There are five large moons - Ariel,Umbriel, Titania, Oberon and Miranda. The ten smaller ones were discovered by the Voyager 2 space probe in 1986. </span><br />
<span style="font-size: large;">Uranus’ moon Miranda is the weirdest moon of all. It seems to have been blasted apart, then put itself back together again! Because Uranus is so far from the Sun, it is very, very cold, with surface temperatures dropping to -210°C. Sunlight takes just eight minutes to reach Earth, but 2.5 hours to reach Uranus. Uranus’ icy atmosphere is made of hydrogen and helium. Winds whistle around the planet at over 2000 km/h - ten times as fast as hurricaneson Earth.</span><br />
<span style="font-size: large;"> Uranus has its own, very faint set of rings Uranus has an atmosphere of hydrogen and helium gas Uranus’ surface is an ice-cold ocean of liquid methane (natural gas), thousands of kilometres deep, which gives the planet its beautiful colour. If you fell into this ocean even for a fraction of a second, you would freeze so hard that you would shatter like glass. </span><br />
<span style="font-size: large;">Uranus was named after Urania, the ancient Greek goddess of astronomy. A Uranus is the third largest planet in the Solar System - 51,118 km across and with a mass 14.54 times that of the Earth’s. The planet spins round once every 17.24 hours, hut because it is lying almost on its side, this has almost no effect on the length of its day. Instead, this depends on where the planet is in its orbit of the Sun.</span><br />
<span style="font-size: large;"> Like Saturn, Uranus has rings, but they are much thinner and were only detected in 1977. They are The planet’s surface made of the darkest material in the Solar System. of liquid methane gives it a stunning blue colour Uranus is only faintly visible from Earth. It looks no bigger than a star through a telescope, and was not identified until 1781 (see Herschel). On Uranus in spring, the Sun sets every nine hours span style font-size: large;Neptune is the fourth largest planet.</span><br />
<span style="font-size: large;"> At 49,528 km across, it is slightly smaller than Uranus - hut it is actually a little heavier. Like Uranus, its oceans of incredibly cold liquid methane make it a beautiful shiny blue, although Neptune's surface is a deeper blue than that of Uranus.

Again like Uranus, Neptune has a thin layer of rings. But Neptune’s are level, and not at right angles to the Sun. </span><br />
<span style="font-size: large;">Neptune has a Great Dark Spot, like Jupiter’s Great Red Spot, where storms whip up swirling clouds.

Neptune’s moon Triton is the coldest place in the Solar System, with surface temperatures of -236°C

There are little white tail of clouds and great dark spots  on Neptune. </span><br />
<span style="font-size: large;">These clouds are named scooter by scientists. These can clearly be seen in this photo taken by Voyager 2 space craft  in 1989.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> Uranus </span></h3>
<span style="font-size: large;">Uranus is the seventh planet out from the Sun. Its orbit keeps it 1784 million km away on average and takes 84 years to complete.

Uranus tilts so far on its side that it seems to roll around the Sun like a gigantic bowling ball.</span><br />
<span style="font-size: large;"> The angle of its tilt is 98°, in fact, so its equator runs top to bottom. This tilt may be the result of a collision with a meteor or another planet a long time ago.

In summer on Uranus, the Sun does not set for 20 years. In winter, darkness lasts for over 20 years. In autumn, the Sun rises and sets every nine hours.</span><br />
<span style="font-size: large;"> Uranus has 17 moons, all named after characters in William Shakespeare’s plays. There are five large moons - Ariel,Umbriel, Titania, Oberon and Miranda. The ten smaller ones were discovered by the Voyager 2 space probe in 1986.

Uranus’ moon Miranda is the weirdest <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank"><b>moon</b></a> of all.</span><br />
<span style="font-size: large;"> It seems to have been blasted apart, then put itself back together again!

Because Uranus is so far from the Sun, it is very, very cold, with surface <a href="http://educational-wealth.blogspot.com/2014/02/temprature-of-earth.html" target="_blank"><b>temperature</b></a>s dropping to -210°C. Sunlight takes just eight minutes to reach Earth, but 2.5 hours to reach Uranus.

Uranus’ icy atmosphere is made of hydrogen and helium.

Winds whistle around the planet at over 2000 km/h - ten times as fast as hurricaneson Earth. </span><br />
<span style="font-size: large;">Uranus has its own, very faint set of rings

Uranus has an atmosphere of hydrogen and helium gas

Uranus’ surface is an ice-cold ocean of liquid methane (natural gas), thousands of kilometres deep, which gives the planet its beautiful colour. If you fell into this ocean even for a fraction of a second, you would freeze so hard that you would shatter like glass.</span><br />
<span style="font-size: large;"> Uranus was named after Urania, the ancient Greek goddess of astronomy.

A Uranus is the third largest planet in the Solar System - 51,118 km across and with a mass 14.54 times that of the Earth’s. The planet spins round once every 17.24 hours, hut because it is lying almost on its side, this has almost no effect on the length of its day. </span><br />
<span style="font-size: large;">Instead, this depends on where the planet is in its orbit of the Sun. Like <a href="http://educational-wealth.blogspot.com/2014/02/very-beautiful-saturn-rings.html" target="_blank"><b>Saturn</b></a>, Uranus has rings, but they are much thinner and were only detected in 1977. They are The planet’s surface made of the darkest material in the Solar System.

of liquid methane gives it a stunning blue colour

Uranus is only faintly visible from Earth. It looks no bigger than a star through a telescope, and was not identified until 1781 (see Herschel).

On Uranus in spring, the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a> sets every nine hours

</span></div>

Neptune and uranus

Neptune Neptune is the eighth planet out from the Sun, varying in distance from 4456 to 4537 million km. Neptune was discovered in 184...

planets, orbits

Abdullah 0 Article, Astronomy Wednesday, February 05, 2014

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<h3 style="text-align: left;">
<span style="font-size: large;">Planets </span></h3>
<span style="font-size: large;">Planets are globe-shaped space objects that orbit a star.

Planets begin life at the same time as their star, from the left over clouds of gas and dust.

Planets are never more than 20 percent of the size of their star. Some planets, called terrestrial planets, have a surface of solid rock. </span><br />
<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto; text-align: center;"><tbody>
<tr><td style="text-align: center;"><a href="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg888v3jqLlplvrKB213G4ePhbI4gUdm5mE8VuHfUBSjpdA54HKAcmBr8XdZ-Q6DNdxOZV7zJ0ClzkA3l2oGH1hIX7Gz87L-IskUCkfmaOapQLcYlFk1AwBnX6Tc9Jv4BjIk2qLXJiUN8M/s1600/pplanet.bmp" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" height="396" loading="lazy" src="https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEg888v3jqLlplvrKB213G4ePhbI4gUdm5mE8VuHfUBSjpdA54HKAcmBr8XdZ-Q6DNdxOZV7zJ0ClzkA3l2oGH1hIX7Gz87L-IskUCkfmaOapQLcYlFk1AwBnX6Tc9Jv4BjIk2qLXJiUN8M/s1600-rw/pplanet.bmp" width="640" /></a></td></tr>
<tr><td class="tr-caption" style="text-align: center;">planets in orbits</td></tr>
</tbody></table>
<br />
<span style="font-size: large;">Others, called gas planets, have a surface of liquid or airy gas.

The solar system has nine planets including Pluto. But Pluto may be an escaped moon or an asteroid, not a planet.

Giant planets have now been detected orbiting stars other than the Sun. These are called extra-solar planets.

Extra-solar planets are too far away to see, but can be detected because they make their star wobble.

One extra-solar planet has now been photographed. Among the nine stars so far known to have planets are 47 Ursae Majoris, 51 Pegasi, and 70 Virginis.</span><br />
<span style="font-size: large;"> Four of the new planets - called 51 Peg planets, after the planet that circles 51 Pegasi - seem to orbit their stars in less than 15 days. The planet orbiting Tau Bootis gets around in just 3.3 days.

A Most of the nine planets in our Solar System have been known since ancient times, but in the last few years planets have been found orbiting other, far away stars.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> The planets of our Solar System: </span></h3>
<span style="font-size: large;">from the front,<a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b> Neptune</b></a>, <a href="http://educational-wealth.blogspot.com/2014/02/two-most-important-planetsneptune-and.html" target="_blank"><b>Uranus</b></a>, <a href="http://educational-wealth.blogspot.com/2014/02/very-beautiful-saturn-rings.html" target="_blank"><b>Saturn</b></a>, Jupiter, <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Mars</b></a>, Earth and its <a href="http://educational-wealth.blogspot.com/2014/02/moon-of-earth.html" target="_blank"><b>moon</b></a>, <a href="http://educational-wealth.blogspot.com/2014/02/mars-planet.html" target="_blank"><b>Venus</b></a> and Mercury. Pluto (not shown) is the furthest out from the Sun.

These all planets move in orbits around the sun.</span><br />
<h3 style="text-align: left;">
<span style="font-size: large;"> Orbits</span></h3>
<span style="font-size: large;"> Orbit means ‘travel round’, and a moon, planet or other space object may be held within a larger space object’s gravitational field and orbit it.</span><br />
<span style="font-size: large;"> Space stations are artificial satellites that orbit the Earth. The Moon is the Earth’s natural satellite.

Orbits may be circular, elliptical (oval) or parabolic (conical). The orbits of the planets are elliptical.

An orbiting space object is called a satellite. </span><br />
<span style="font-size: large;"> The biggest-known orbits are

those of the stars in the Milky Way, which can take 200 million or more years.

Momentum is what keeps a satellite moving in space. How much momentum a satellite has depends on its mass and its speed. </span><br />
<span style="font-size: large;">A satellite orbits at the height where its momentum exactly balances the pull of the larger object’s gravity.

If the gravitational pull is greater than a satellite’s momentum, it falls in towards the larger space object.

If a satellite’s momentum is greater than the pull of the larger object’s gravity, it flies off into space. </span><br />
<span style="font-size: large;">The lower a satellite orbits, the faster it must travel to stop it falling in towards the larger space object.

Geostationary orbit for one of Earth’s artificial satellites is 35,786 km over the Equator. At this height, it must travel around 11,000 km/h to complete its orbit in 24 hours. </span><br />
<span style="font-size: large;">Since <a href="http://educational-wealth.blogspot.com/2014/02/our-lovely-planetearth-creation-origin.html" target="_blank"><b>Earth</b></a> also takes 24 hours to rotate, the satellite spins with it and so stays in the same place over the Equator.

Earth is about 150 million km from the Sun. However, this distance varies as our planet's orbit is slightly oval. The time it takes for Earth to orbit the Sun once is 365 days. In comparison, Pluto takes 248 years to orbit the <a href="http://educational-wealth.blogspot.com/2014/02/sun-and-its-rays.html" target="_blank"><b>Sun</b></a>. </span></div>

planets, orbits

Planets Planets are globe-shaped space objects that orbit a star. Planets begin life at the same time as their star, from the left over...

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Galaxies

Earth's creation

Mars and venus (planets)

Temprature of the earth

Space telescopes and Crafts

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Sun and it’s rays

Neptune and uranus

planets, orbits

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